Table of Contents
Downloaded from
Elcodis.com
electronic components distributor
Section 3 MCU Operating Modes
3.1 Overview
3.1.1 Operating Mode Selection
The H8/3032 Series has three operating modes (modes 1 to 3) that are selected by the mode pins
(MD
and MD
) as indicated in table 3-1. The input at these pins determines expanded mode or
1
0
single-chip mode.
Table 3-1 Operating Mode Selection
Mode Pins
Operating Mode
MD
MD
1
—
0
0
Mode 1
0
1
Mode 2
1
0
Mode 3
1
1
Notes: 1. In mode 1, if the RAM enable bit (RAME) in the system control register (SYSCR) is
cleared to 0, these addresses become external addresses.
2. In modes 2 and 3, clearing bit RAME of SYSCR to 0 and reading the on-chip RAM
always returns H'FF, and write access is ignored. For details, see section 13.3,
Operation.
For the address space size there are two choices: 64 kbytes or 1 Mbyte.
Modes 1 and 3 support a maximum address space of 1 Mbyte. Mode 2 supports a maximum
address space of 64 kbytes.
The H8/3032 Series can only be used in modes 1 to 3. The inputs at the mode pins must select one
of these three modes. The inputs at the mode pins must not be changed during operation.
Description
Address Space
Initial Bus Width
0
—
—
1 Mbyte
8 bits
64 kbytes
—
1 Mbyte
—
55
*1
On-Chip RAM
—
*1
Enabled
*2
Enabled
Enabled
*2
Table of Contents
